One of the most prominent ingredients in a conditioning hair care products such as a conditioning shampoo (also called a "2 in 1" shampoo product) is a silicone and/or its derivatives. While it is desirable to add high molecular weight silicone derivatives to shampoos to achieve conditioning effects, it can be difficult to formulate surfactant insoluble silicone-containing shampoos that are stable and do not have the problem of separating out the silicone component. Various attempts at incorporating these silicone conditioning agents into such conditioning shampoos have included dispersing, suspending or emulsifying such agents; these approaches result in the opacification of the products and sometimes results in unstable products due to the separating out of the silicone. Higher levels of a silicone material such as dimethicone are useful in providing increased amounts of conditioning to the hair. However, higher levels of dimethicones are very difficult to physically stabilize in detergent systems.
There have been various attempts at solving the separation problem. For example, one method of stabilizing dimethicones uses alcohols having 20-40 carbons, such as are commercially available. Such compositions are found in U.S. Pat. No. 5,213,716 to Patel et al, U.S. Pat. No. 4,997,641 to Hartnett et al, and assigned to the same assignee as this application. Another method is found in U.S. Pat. No. 4,741,855 to Grote et al, which teaches the use of long chain (C.sub.16 -C.sub.22) acyl derivatives such as ethylene glycol distearate or long chain (C.sub.16 -C.sub.22) amine oxides, as suspending agents. U.S. Pat. No. 5,152,914 to Forster et al teaches the use of suspending agents chosen from polyethylene glycol mono- or diesters of (C.sub.16 -C.sub.22) fatty acids having from 2-7 ethylene oxide groups. U.S. Pat. No. 4,704,272 to Oh et al. Teaches the use of xanthan gum and long chain acyl derivatives as suspending agents for insoluble, non-volatile silicone.
There have also been approaches to silicone chemistry in personal care and shampoo products which have used different chemistries in order to obtain better products.
U.S. Pat. No. 5,543,074 to Hague et al describes personal washing compositions comprising silicone oil and a suspending agent selected from polyacrylic acid, copolymers of acrylic acid with hydrophobic monomers, and copolymers of acrylic acid and acrylate esters.
U.S. Pat. No. 5,073,296 to Kopolow et al teaches a method of stabilizing an oil-in-water emulsion using a water-soluble vinyl compound and a free-radical polymerization initiator. The oil may be a cosmetically active material such as silicone oil. A comonomer such as a methacrylate or a neutralized acrylic acid may be added to the vinyl compound.
Further references for hair care compositions with insoluble silicones include U.S. Pat. No. 4,997,641 to Hartnett et al and U.S. Pat. No. 5,415,857 to Robbins et al, both assigned to the same assignee as this application.
Other references which relate to personal care and which may comprise silicone oils which are stabilized by the addition of vinyl monomers and acryl comonomers which are polymerized in-situ include U.S. Pat. No. 5,084,208 to Negrin et at; U.S. Pat. No. 5,169,622 to Kopolow et al; U.S. Pat. No. 5,169,623 to Kopolow et al; U.S. Pat. No. 5,474,712 to Dotolo et al (conditioning shampoo which consists of, inter alia, a polyalkyleneoxide-modified polydimethyl siloxane and polyacrylic acid and acrylic copolymer emulsifier); U.S. Pat. No. 5,037,648 to Joiner (skin conditioning preparation with, inter alia, polyacrylic acid and dimethicone); and U.S. Pat. No. 5,234,682 to Machio et al (includes a cosmetic composition consisting essentially of, inter alia, dimethicone and acrylates copolymer).
Other hair care references include U.S. Pat. No. 5,051,250 to Patel et al and U.S. Pat. No. 5,346,642 to Patel et al, both assigned to the same assignee as this application.
Some of these methods require the use of heat to get the silicone and the C.sub.20 -C.sub.40 into solution and thus increase the batch time.
There still remains a need to have a 2-in-1 shampoo composition which successfully incorporates a water insoluble non-volatile silicone into a composition which has good stability.
It is a further object to obtain a hair care composition which successfully incorporates a water insoluble silicone into a composition for hair which and which can be manufactured by a low energy process.
Thus, it is an object of this invention to provide an improved method of stabilizing a water insoluble silicone material such as dimethicone and a composition made by such method which is suitable for hair care use. It is a further object of this invention to provide a method for stabilizing a silicone material such as dimethicone which does not require high temperatures. It is yet another object of the invention to provide a method for stabilizing a silicone material such as dimethicone which reduces batch time. These and other objects of the invention will be apparent from the following description.